Process for producing molds for casting stereotype-plates.



warren CARL WVTNKLER, 0F BERNE, SWITZERLAND.

EROCESS FOR PRODUCING MOLDS F llfltilld fiig du No Drawing,

To all whom it may concern:

Be it known that I, CARL WINKLER, a citizen of the Swiss Republic,residing at Berne, in the Swiss Republic, have invented a new and usefulImproved Process for Producing Molds for Casting Stereotype-Plates, ofwhich the following is a specification.

It is usual, in making molds for casting stereotype plates, to carry outall operations, such as turning, planing or shaping, while the mold isin a cold condition. The mold must however be raised to a certaintemperature before being used for casting, as otherwise the platesproduced cannot be employed for printing. when it isin a hot conditionmust be subsequently turned or shaped, in order to receive the exactdimensions required. This subsequent treatment of the plates isnecessary, principally because the mold, in a hot condition, owing tothe expansion and contrac tion of the metal, acquires dimensions whichdifl'er from those the plates should have. Now experiments have shownthat stereotype plates of the desired dimensions can be better obtainedby forming (for example, boring, planing, etc.) the mold in a hotcondition. It is of course desirable to heat the mold while being formedto a temperature which corresponds to that to which it must be raisedfor casting.

on CASTING STEBEOTYPE-PLA Specification of Letters Patent.

Plates cast in such molds.

Patented July Application filed December 26, 1913. serial No. 808,?61.

the invention steam, hot gases, hot air, or a hot liquid may be introduced into hollow chambers provided in the mold during the turningoperation" If the mold has no special hollow chambers a heating devicemay be employed, which can have any suitable construction, and mayconsist, for example, of pipes containing some hot Tn carrying out agentand brought into contact with the i mold.

The difference in printing plates cast in molds made in a hot condition,compared with plates cast in molds made in a cold condition, asheretofore usual, are so considerable that a subsequent planing orboring of said plates is not necessary.

What I claim and desire to secure by Letters Patent of the United Statesis The process for producing molds for easting stereotype plates, whichconsists in finishing said molds at about a temperature to which saidmolds are raised when the plates are cast in said molds.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

I CARL winietns \Vitnesses F. STEPHAN, RICHARD Loan.

